I just installed D'Addadrio halfrounds on my PJ bass: I like them. They replaced a nickle round set, same gauge.
The low E still has growl but is better defined. I really like the string feel -- nice and smooth.

i use d'adarrio HR's on my Sterling and I dig em- great silky feel and tone with a nice balance of thump and treble. do they feel exactly like flats? no. but, very nice and about as close as you are going to get. i also use d'addario chromes on my g&l and they are actually a bit more abrasive, for lack of a better word, than the HR's.

I just put med gauge D'adarrio half rounds on my jazz and I really like them. I'm not a big fan of rounds, but I wanted my jazz to have a little brightness in the tone. These half rounds seem to do a pretty good job of splitting the difference between rounds and flats.

Yeah on Smith Compressors - or GHS Pressurewounds. If you want the brightest of them get the light gauge ones (which still have plenty of tension since there is more mass there than roundwounds of the same gauge). If you want a little less top get the heavier gauge set - less flexibility, and thus less of the higher overtones.